V10/cmd/m4/m4.test1

define(lgth,`ifelse($1,,0,`incr(lgth(substr($1,1)))')')
define(string,`integer $1(lgth(substr($2,1)))
str($1,substr($2,1),0)
	data $1(lgth(substr($2,1)))/EOS/
')
define(str,`ifelse($2,",,`
	'data $1(incr($3))/`LET'substr($2,0,1)/`str($1,substr($2,1),incr($3))')')

string(xxx,"abc")
string(yyyy,"123456789")